Do not indent subscription description
Fix <h1> margin

There wasn't any margin underneath. Fix it so there is some.
Fix commit 75db7431: don't use <p> around generated HTML

Instead, use a proper <div>.
Provide proper fallback for old subscriptions

Use django.utils.html.linebreaks to automatically add <p> and <br/>
tags.
Merge pull request #243 from aykevl93/subscriptions-layout

Activiteiten layout